The present invention relates to a mobile device for renewal of railway tracks by continuous advance along these, comprising a work tool carrying chassis adapted to ensure at least the replacement of the old ties by new ones and at least two wagons at least one of which is adapted for transport, stocking and/or the handling of the material necessary for the said track replacement.
There is already a known device of this type which has been especially described in Swiss Patent No. 511332 and which comprises a so called girder renewal joined by its two ends to two overhanging brackets of two wagons disposed one on each side of the said girder, one rolling on the old track to be renewed and the other on the reconstituted new track, and each of these two wagons have two bogies. In this device the work tool carrying chassis is suspended from the renewal girder and permits lifting of the old ties, remaking of the ballast bed and positioning of the new ties at the tangent point of the axis of the carrying chassis with the longitudinal axis of the track. A system of conveyors and of distributers installed on one of the wagons and under the renewal girder permits stocking the disposed old ties and supplying of the new ties to be positioned while a rail guiding device permits removal from the track of the old rails previously unspiked and disposes them alongside the track and places the new rails at the normal spacing on the newly laid ties.
This renewal device works satisfactorily but necessitates a large and relatively heavy structure between the two wagons in the work zone because it comprises, in addition to the tool carrying chassis, a bridge girder, two overhanging brackets and two delicate and heavily loaded joints. One of the joints must be a swivel joint and the other a Cardan joint to permit the free pivoting of the girder in all directions while preventing this from turning along its longitudinal axis with respect to one of the two wagons.
This large structure, necessary in turn for freeing of all load on the work zone and to obtain automatically the tangency of the axis of the tool carrying chassis with the axis of the track in the curves, constitutes in fact a dead load contributing to the cost of such a device and the expense of energy necessary for its use.
There is also a well known railway track renewal device in which the tool carrying chassis is suspended from a bridge girder joined to two wagons which frame it but in which the overhanging bracket of one of the two wagons is omitted. In this device the renewal girder is joined by one end at the end of the overhanging girder or the wagon on which this had been retained and by its other end, on the wagon without a bracket, perpendicular to the axis of the track, that is to say at the perpendicular of the pivotal axis of a bogie of the said wagon. This embodiment has the effect that the longitudinal axis of the renewal girder cannot be tangential to the longitudinal axis of the track in the curves but on the contrary always secant thereto and that due to this the tool carrying chassis or at least the tool for laying the new ties must necessarily be adjustably mounted if one wants to ensure the tangency in the curves of the track.
An object of the invention is to simplify the bridging structures joining the two wagons framing the work zone whilst conserving the advantage of an automatic positioning of the longitudinal axis of the tool carrying chassis on the tangent to the axis of the railway track in curves.